Articulator



Feb.. 15, 1927. 1,617,590

P. A. GOULD ARTICULATORA Filed Jim 22, 1925 Patented Feb. 15, 1927.

as. 'sr

PEBCI'VAL A. GOULD, on GIBSONBURG, OHIO.

ARTICULYATOR.

Application filed June as, 1925. SeriaI'Ho. 38,626.

This invention relates .to prosthetic dental apparatus but more particularly is concerned with articulators.

cal devices have been designed for this purpose. Among these devices is an articulator produced byAl-fred Gysi, commonlyknown as the simplex articulatoi and Wjhi'chhas been popularly received by dentists through out the country, but although this articulator performs fairly satisfactory work, it ,has

failed to cope with an important and difficult problem which is outstanding as a matter of practice and which materially detracts from efficient performance.

. Experiments have proved that the human mandible in every instance has a lateral or sidewise movement as well as a downward and outward protrusion and also that the rotation points or the mandible are located below and behind the condyles these rotation points being the theoretical centers ot -motions exhibited in,thehuman mandible. -In view of these empirically discovered facts Gysi evolved his articulator and produced mechanically the movements of .the human mandible.

In .the Gysi apparatus there is provided a vertically disposed pin which is kno'wi'i as the incisor guide pin'and .this pin is connect: ed for-movement with-a .member-(model support)- corres ponding to and moyable'in accordance with the'h'uman mandible; The guide ,pin'engages a stationary I guide .and in practice the guide pin is moved back and forth as wellassidewise to position the artificial denturesrelativelytoeach'other, it

being understood that. the "plates are mount ed respectively on a stationary model support to which the guide is connected and the model support corresponding to the human mandible. If the patient ;for whom the dentures are intended is of the-average and bites with an even muscular forc'e on both sides, such dentures usually prove satisfactory.

Experi ence has shown however that den- ,tures articulated in accordance with.tlie'Grysi apparatus "are not. s atisfa'ctory in v about I fifty percent of the cases and this is essentially because invariably persons do not have the same. angular movement of the lower mandible and' do bite on both sides with anequal muscular force and'therefore if the artificial dentures are articulated with the assumption that su'c'lrtorce is equal on both sides; and the angular movement is of the average thedentures are'not accurate. If the dentui' es are not articulated withthese-tacts in mind and due compensationunade therefor, the

side which issubjected to the greater-uniscu'lar biting force, is exposed toabsorption' and this nilita'tes against properfitt ing so thatafter a comparatively short time the dentures will not remain in the mouth.

Objects of this inventionare to overcome the above diificulty; to'pro'vide a simple and inexpensive articulator in which artificial denturesmay be articulated accurately irrespective of the: difference in musculanbiting force and angular movement at themandible ot thepatient; and to provide in an articulator means for compensating"forthe difference' in' muscular biting force andangnlar movement of the lower mandible of patients so that -articulation maybe accurately and readily accomplished in every instance;

The invention is shown 'by theway of illustration in the accompanying drawings in which; 1 Q Fig. 1 is a vertical elevational view of the articulator. of the construction shown in'Fig. 1. Fig 3 is a fragmentary'plan View of the stationary model support and guide plate; Fig, 4 is a side elevation of the construction shown in Fig. 3; Fig. 5 is a diagrammatic plan view showing the operation of the parts with the guide plate moved to one position;

SOv

Fig. 2 is a top plan view 3 andFig; '6 is a diagrammatic plan view, similar, to Fig. 5 showing operation of the parts with theguide' plate moved to the-opposite direction, I

Theillustrate'd embodiment of the invention comprises a frame]. having sockets to receive thev projecting portions of a triangu lar model'su'pport 2 and-screws 3 are provided'in'the frame 1 for engagingthese projecting portions andholdingthe support 2, se} curely inposition. The model support Q'exframe land is employed for holding the lower plate of a set of artificial dentures,

Pivotaily'mounted on the upper part of the frame 1 is a model support 4 having a vertically depending guide pin 5 at the outer' end thereof.

- tends at substantiallyright angles from the adapted to be held in adjusted position by aset screw 6 and slidably mounted on the guide pin is a pointed block 7 which may -'normally be secured in agroove 8-by a set I 4 fl fl d y andto one side of the curved screw 9.

portions 10 aredow'nwardly projecting pins 12- which project into recesses 13 formed in the frame 1.

v The guide pin 5 is held in engagement with a guide plate 14 by means of a leaf spring 15 which is fixed to the frame land engages the upper portion of the model support 4. Theforward face of. the guide plate 14 is preferably inclined to an angle of about degrees to the occlusal plane represented by the uppermodel support 4 and is pivoted by means of a bolt 16 to the lower mod-e1 sup port 2. D

In uslng the above described artlculator,

the artificial dentures for the upper and lower jaws offthe patient aresupport-ed on "plaster models mounted on the model supports-4 and 2respectively in a manner well known to the dental profession. Thereafter articulation is accomplished by moving the model support 2 relatively to the model support 4 and this movement is guided by the plate 14 over which the pin 5 is movable. In this manner the lower model support 2 is moved relatively to the occlusal plane represented by the' upper model support 4 in accordance with the movement of the. patients mandible thereby to obtain proper articulation in themouth.

The above operation is common practice and although it has provided satisfactory where the patient for whom the dentures are intended is of the average, such -method does not obtain proper articulation for patients who are not included in this category. This fact will at once be apparent when it is realizedthat the greater number of persons bite with unequal 'n'iuscular force on both sides and therefore if the dentures are articulated without making due'compensation the dentureswill not be comfortable to the patient and will not remain in place for any extended period of time because absorption will take place on the side which is subjected to the greater biting force.

This invention overcomes this difliculty preferably by mounting the incisor guide plate 14 in such a manner that it may be adjusted to the right or left of its central position. The effect of swinging the plate 14 to the left is diagrammatically illustrated in Fig. 5 which shows that in this position, movement on the left side is considerably greater than on the right because movement of the left condyle path member 10 is permitted a wide swing, but a slight amount of movement is allowed to the right member 10 owing to the angular position of the guide plate. I 7

It will be apparent that movement of the incisor guide pin 5 along the guide plate 14 in the usual manner for articulation will properly form the dentures relatively to each other when the biting force is greater on the right side than on the left when the plate is in the position indicated in Fig.' 5. Of course, the amount of adjustment-of the guide plate 14 may be ascertained in any suitable manner as by trial or visual indication but this degree of movement can be readily determined as a practical matter by one familiar with prosthetic articulation. By adjusting the plate 14 articulation'may be accomplished for patients having a greater biting force on the left than on the right side (Fig. 6) as will readily be apparent. Adjustment of the incisor guide plate "to compensate for variations in muscular biting force has proved much simpler, more accurate and more reliable than adjustment of the relative positions of the condyle members and condyle path which has heretofore been attempted because in the latter instance it is a difficult. matter to effect delicate adjustment or to any practical degree of accuracy to know how much adjustment is necessary for the desired articulation. By adjusting the incisor guide plate, adjustment is effected at the proper place and this is principally because naovement mainly centers around and is controlled by the incisor guide plate 14 at the point where movement is the greatest. V

As heretofore mentionedthe average inclination or angle of the incisor guide plate His 80 degrees relatively to the occlusal plane but for difi'erent'persons adjustment should be made because where the swinging movement of the mandible is short, the angle of condyle path much greater and where the manibular movement is relatively long the angle of the condyle path is less I than 30 degrees. 1 for this difference 111 muscular biting force,

be formed in two separate parts which are held in assembled relation by a bolt 18 and a nut 19. By loosening the nut 19 the plate 14; may be swung to the desired'position.

' of the dentures proceeded with.

In order to lock the plate in adjusted position a, rearwardly extending ear may be formed in the under side of the plate 14 and a set screw 21 in threaded engagement with the ear 20 may be moved against the under side of the model support 2. It will be. apparent that downward pressure acting against the guide plate 1% will not operate to displace the guide plate from its adjusted position.

When it is found that the angle of the condyle paths of a patient is greater or less than degrees, the guide plate let is first moved to its central position which arranges the model supports at central occlusion and then swung vertically upward or downward to increase or diminish the angle from the average in its relation to the occlusal plane. By means of the bolt 18, nut 19 andset screw 21, the plate 1 1 may then be securely held in its properly adjusted position and articulation In cases where the angles of the condyle paths are unequal, then ,the guide plate 14 may be swung to the right or left on its pivot bolt 16 on an average plane of'30 degrees to the occlusal plane, the result will be that the incisal guide pin 5 will have an angular plane of less than 30 degrees on one side and greater than 30 degrees on the other.

Nhile I have shown and described an embodiment of my invention as required by the statutes so that others skilled in this art may make and use the same, it is to be understood that the above is given merely for purposes of illustration and not of limitation, and numerous changes in details of design, arrangement and operation may be effected without departing from the spirit of the lnventlon,

especially as'defined in the appended claims. What I claim as newand' desire to secure by Letters Patent is: I V 1. In an articulator, a frame, upper and lower horizontally disposed supports extending atright angles from said frame, a guide plate having an inclined bearing surface carried by the free end of the lower support and further having its bottom formed to provide a rearwardly extending arm, a depending rod carried by the free end of the upper support adapted to engage the inclined surface of the guide plate, and means on the rearwardly extending arm of the guide plate to permit vertical adjustment thereof whereby to, effect relative movement of the supports with respect to each other.

2. In an articulator having upper and lower horizontally disposed supports, a guide plate having an inclined bearing surface pivotally secured to the free end of the lower support, said plate further having a rearwardly extending arm disposed below said lower support, and a vertically disposed screw carried by the rearwardly extending arm contacting with the lower support whereby to effect adjustment of the bearing surface of the guide plate with respect to said lower support.

8; In combination with an articulator, a guide block having an inclined front face and a vertical rear face, a rearwardly extending arm forming a continuation of the bottom of the guide block and-means carried by said arm adapted to contact with the articulator whereby to effect vertical movement of the guide block.

In testimony whereof, I have hereunto signed my name to this specification.

PERCIVAL A. GOULD. 

